Which is true regarding the graphed function f(x)?
1 answer:
<h2>Explanation:</h2>
Hello! Remember you have to write complete questions in order to get good and exact answers. Here I'll assume the graphed function comes from:
So this is the equation of a parabola that opens upward and whose vertex lies on the point:
The graph of this function is shown below. Which is true regarding the graphed function f(x)?
- It is true that the domain is the set of all real numbers because this is a polynomial function.
- It is true that the range is the set of all real numbers such that y ≥ 5
- It is true that this parabola opens upward
- It is true that it doesn't cut the x-axis
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Answer:
We conclude that the actual percentage of households is equal to 30%.
Step-by-step explanation:
We are given that a consumer group suspects that the proportion of households that have three cell phones NOT known to be 30%.
Their marketing people survey 150 households with the result that 43 of the households have three cell phones.
Let p = <u><em>proportion of households that have three cell phones NOT known.</em></u>
So, Null Hypothesis, : p = 30% {means that the actual percentage of households is equal to 30%}
Alternate Hypothesis, : p
30% {means that the actual percentage of households different from 30%}
The test statistics that would be used here <u>One-sample z-test for proportions;</u>
T.S. = ~ N(0,1)
where, = sample proportion of households having three cell phones =
= 0.29
n = sample of households = 150
So, <u><em>the test statistics</em></u> =
= -0.27
The value of z test statistic is -0.27.
<u>Also, P-value of the test statistics is given by;</u>
P-value = P(Z < -0.27) = 1 - P(Z 0.27)
= 1 - 0.6064 = <u>0.3936</u>
<u>Now, at 1% significance level the z table gives critical value of -2.58 and 2.58 for two-tailed test.</u>
Since our test statistic lies within the range of critical values of z, so we have insufficient evidence to reject our null hypothesis as it will not fall in the rejection region due to which <em><u>we fail to reject our null hypothesis</u></em>.
Therefore, we conclude that the actual percentage of households is equal to 30%.